We examines the dynamics of population location using a simple general equilibrium model with agglomeration economies that permits a description of the lock-in effects associated with existing agglomerations. By assuming that the government applies slightly different decision rules (cost-benefit evaluation rules) and that it improves the transport network, especially the railway network, through one by one link improvements in the order that the links with the highest benefit-cost ratios are given the highest priority to be improved, this paper tries to demonstrate that city systems will evolve in such a manner that population will indeed cluster in some dominant locations, and that this depends both on the geographical conditions and historical order of network improvement.The model highlights one of the major sources of increasing returns, i.e., spatial agglomeration generated through technological externalities in production. The model is designed to exclusively simulate how the str
… Moreucture of city systems will evolve in response to railway network improvement. In this research, we exclusively focused upon the latter types of externality to describe how city systems will evolve in response to increasing possibilities of face-to-face communications due to railway network improvements.The cost-benefit evaluation rule guarantees the government to make the local optimal decisions, given the history of the network evolution. The successions of the local optimal improvement need not to reach the global optimal state. This is especially true if the city system is inherently characterized by the multiplicity of the equilibria. Though only limited number of simulation experiments are dealt with, we have succeeded to illustrate that the simple succession of the cost-benefit evaluation rules may end up with highly centralized systems having low efficiency. As far as our simulation experiments are concerned, this is especially clear when decisions are made by coarse and naive cost-benefit calculation.次年度には,初年度に構築したプロトタイプモデルをもとに実用的なモデルへと拡張を行い,あわせて実際のデータを用いた実証分析を行った.初年度に作成したプロトタイプのモデルをさらに拡張し,実証分析に使用できるような実用的な都市システム成長モデルを提案した.現実の都市システムの発展過程と交通システムの整備状況について実証的な分析を試みるために,高速鉄道システムや航空網システムと都市成長過程の関係を分析した. Less